1. Field of the Invention
This invention relates to motorcycles and the positioning of an alarm system thereon.
2. Background of Related Art
Motor vehicles, and in particular motorcycles, are the most common subject of tampering and outright theft by parties preying on private property. Various devices have been created to alert the vehicle's owner if their vehicle or equipment is being tampered with or stolen. In large measures, these devices have been complicated, expensive to install, and susceptible to being triggered by small animals, such as birds and cats, and weather conditions, such as rain, wind, and low temperatures. The subject invention deals primarily with the motorcycle industry, although is not limited solely thereto as the heretofore description will illuminate, and in particular to the monitoring of movement of key non-conductive surfaces on the motorcycle for purposes of detecting intent of motorcycle theft, or of the taking of accessory equipment from the motorcycle.
In the main, prior "anti-theft" motorcycle devices consisted of movement sensing sensors (Barnett, U.S. Pat. No. 3,699,515) for the detection of tampering through monitoring accellerations, and of sensing change in the motorcycle's level of tilt as it would remain at rest on its stand. Tilt measurement change would rely primarily on a single mercury switch (Buel, U.S. Pat. Nos. 3,673,562; DeMeter, 3,916,377; Giacino, 4,006,452) for recovery along a single plane, or on coplanar mounted double mercury switches (Horn et al., 3,728,675) for detection of recovery from a tilted stand position, or if they fall below the prescribed level of tilt. (The motorcycle is knocked down or pushed away at a low angle.) A third class of detection device involves monitoring electric field dissipation from the vehicle as a charged body, but because of its complication and obvious environmental complications, as well as its dissimilarity from the subject invention, will hitherto not draw further attention along with its closely allied counterparts.
Accellerometer type devices (such as Barnett, U.S. Pat. No. 3,699,515) are sensitive to adjustment and are easily set off by wind buffetting, passing heavy vehicles, small playing animals, and other "false alarms." Tilt-measurement type devices (such as Buel, DeMeter, Giacino and Horn) measure deviation from a given plane established when the motorcycle is at rest. The adjustment must be precise to be effective. Because of this precision requirement, they are also subject to "false alarms" by wind buffetting and bumping by small animals. Also, many motorcycles have both a "side-stand" on which the motorcycle rests at an angle, and "center-stand" which allows the motorcycle to be pulled up into a supported vertical position. Adjustment of the tilt measurement device on any one of the stands would negate its usefullness, without readjustment, if the other stand would be used. Also, none of the above alarms address the problem of accessory protection, e.g., alarming when equipment or parts are stolen off of the motorcycle. Green (U.S. Pat. No. 3,427,608) discusses a "portable burglar alarm" utilizing a switch with inwardly directed contractor spring arms. The invention relates to home security, and the switch arms are held apart by an insulating wedge that is pulled out by a tether when a door to which it is attached is opened. Both construction and function are different in the subject invention as hereinafter disclosed. The foregoing invention addresses these and other problems, as shall be evident in the description that follows.